Re: Kernel thread stack usage


On Nov 11, 2007, at 12:43 PM, Alexander Motin wrote:

Marcel Moolenaar wrote:
This is not theoretical at all: On ia64 there are 2 stacks. One
growing down and one growing up. The downward stack is used for
stack-based variables and the pward growing stack is used by
the processor for stacked registers.

Hmm, interesting. And which one is pointed by td_kstack there? Or they are using same segment but from opposite sides?

The latter. The td_kstack variable points to the bottom,
which is where the register stack starts. The memory stack
start from td_kstack + td_kstack_size.

The code suggested will not be meaningful on ia64.

Why? If variable stack growing down and it's segment is pointed by td_kstack then where is the problem? Or you mean that system will die earlier when those two stacks in same segment will reach each other?

It's the register stack that grows faster in general and
yes, they grow towards each other so they can eventually
run into each other.

--
Marcel Moolenaar
xcllnt@xxxxxxx


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